What Do You Do if Your Furnace Never Turns Off? - Ernst Heating & Cooling - Metro East IL HVAC

What Do You Do if Your Furnace Never Turns Off?


If your furnace never turns ON, that sounds like the worst-case scenario. But what do you do if your furnace never turns OFF?

Simple solutions

We all make mistakes, and sometimes what seems like a complicated problem actually has a simple solution. It might be something you can easily fix yourself. For example, maybe you have your thermostat set wrong! If the fan is set to ON instead of AUTO, then your furnace blower is going to run nonstop. Of course, AUTO will make the blower run only when heated air needs to be circulated. It will shut off once you’ve reached the right temperature. The furnace blower is only supposed to run when there is hot air to circulate. If the fan is set to ON, the blower fan will be running even when there is no hot air.

Another reason your furnace may not be turning off is a dirty air filter. Filters get dirty more quickly in winter. Your furnace is working overtime to keep your house warm, which means a lot of air is getting circulated through your filter. That means, lots of dust getting in your filter too! You should really be changing your air filter every month in winter. A dirty filter makes it harder for air to get through, making your furnace work even harder … and if your furnace has to work harder, then it takes longer to heat your home, which can create the appearance that your furnace never turns off. Please give your system a clean filter!

Solutions that require a professional HVAC service

Outside of incorrect thermostat settings or a dirty air filter, most other causes of constantly running furnace involved broken parts. Your furnace blower or your thermostat could be broken, which requires one of the professionals at Ernst to fix. You could even have a ductwork problem, where air is leaking out of your ducts into your attic. In this case, your furnace is working constantly trying to get hot air in your home, to no avail.

Call Ernst in Metro East IL!

We know all of these problems sound overwhelming, but it’s worth getting fixed! Maintaining your HVAC system ensures that your energy bills stay low, and your furnace stays functioning during the cold Hamel winter that is coming! Let a trusted Ernst technician come out and troubleshoot the problem. Schedule an appointment online or call us at 618.217.1836!

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